Magnesium alloys containing cerium and other elements



Patented June 21, 1938 PATENT OFFICE MAGNESIUM ALLOYS CONTAINING AND OTHER. ELEMENTS John Leslie Haughton and William .Elieaer Prytherch, Teddington, England No Drawing.

Application Aprll 20, 1937, serial No. 138,064. I In Great Britain May 5, 1988 1 Claim.

This invention relates to magnesium alloys rich in magnesium. V

The present invention is based upon the observation that beneficial efl'ects are secured by the incorporation in magnesium alloys rich in magnesium of a proportion of cerium and a proportion of one or moreof the metals, nickel, manganese and cobalt and optionally also a proportion of calcium, and further that instead of using metallic cerium mixtures of rare'earth metals containing cerium may be used, for instance a mixture of cerium and thorium or the mixture known as MischmetalP which is a mixture of rare earth metals containing about 60 to 70% of cerium.

The invention consists in ternary or higher magnesium alloys rich in magnesium containing one or more of the metals, nickel, manganese and cobalt and in addition cerium and optionally also calcium.

The invention further extends to ternary or higher magnesium alloys rich in magnesium containing nickel, manganese or cobalt in the presence or absence of calcium and in addition a pro- 5 portion of cerium in association with other rare earth metals, for instance, thorium and in particularthe rare earth metals present with cerium in the mixture known as Mischmetall.

, ,The invention consists more particularly in magnesium rich alloys containing up to about 12 per cent. of cerium and of one or more of the metals, nickel, manganese and cobalt up to the proportion of, say,"8 per cent.

Normally the minimum proportions of cerium 35 present 'in-alloys in accordance with theinvention v is in the neighbourhood of 2 per cent. while the minimum proportion of the metals, nickel and cobalt'is normally not less than 1 per cent. and the minimum content 01' manganese not less than 0.1 40 per cent. Where calcium is present the minimum proportion thereof in the alloy is normally not less than 0.1 per cent. and the proportion thereof may vary from this limit to, say, 5 per cent.

' The invention further extends to articles formed 5 from such alloys and the heat treatment of such alloys and articles in the manner hereinafter defined. The following particulars are given by way of example to illustrate the properties of particular 50 alloys within the scope of the invention, it being understood that the invention is not restricted to alloys of the particular compositions stated in the examplesz- Example I Nominal composition: Cerium 6%, nickel 6%, 5 magnesium remainder.

Ultimate stress, room temperature (tons per sq. in.) 15.02 Ultimate stress, 200 C. (tons per sq. in.) 13.6 10 Ultimate stress, 300 C. (tons per sq. in.) 6.7

Example II Nominal composition: Cerium 3%, nickel 6%, manganese 1.25%, magnesium remainder.

Nominal composition: Cerium 6%, manganese 1.25%, magnesium remainder.

Ultimate stress, room temperature (tons per sq. in.) 18.2 Ultimate stress, 200 C. (tons per sq. in.) 11.0 Ultimate stress, 300 C. (tons per sq. in.) 5.9 2

Example IV Nominal composition (approximate only): Cerium 3%, manganese 1%, cobalt 2%, calcium 0.5%, magnesium remainder.

Temperature Brinell hardness number Room temperature; 55.0 200 c I 41.3 300 C" 29.0

For the purposes of comparison there may be quoted the following properties of an alloy containing cerium 6%, calcium 1% and the remainder magnesium.

Ultimate tensile stress, room temperature (tons per sq. in.) Ultimate tensile stress, 200 C. (tons per sq..i n.) 11.5 Ultimate tensile stress, 300 0. (tons per 7 sq. in.)

The alloys may cerium, calcium.

6.1 be prepared by adding the nickel, manganese or cobalt, v

-.either as metals or asemagnesium-rich alloys, to

by heating to a lower temperaturefsay, 130-220' C. 10 for one or more days.

The heat treatment is, however, not essential in producing 'alloys possessing desirable properties.

We claim:

Magnesium rich alloys containing between 2 and 12 per cent. of cerium, a proportion of 0.1 to 8 per cent. of at least one metal selected from the group nickel and cobalt, a proportion of manganese of between 0.1 to 4 per cent, and a proportlon of calcium up to 5 per cent., the balance being magnesium.

JOHN LESLIE HAUGHTON. WILLIAM EIJEZER PRY'I'HERCH. 

